This cross-sectional study among rural workers in the mountainous region of the southernmost Brazilian State of Rio Grande do Sul was designed to identify the characteristics of work performed on family farms. The research focused on the socio-demographic profiles of rural workers, identifying the characteristics of rural labor and describing the prevalence of some disease entities in such populations. Some 1479 rural workers from 495 farms were interviewed. In this sample, 87% of the individuals were members of the farm-owning family, mean age was 41 years, 56% were males, and mean schooling was 5 years. Farms had a mean area of 37 hectares, 50% had at least one type of farm machinery, and fruits constituted the main crop. About 75% of workers handled several types of pesticides, while 12% reported at least one lifetime episode of pesticide poisoning. Prevalence of minor psychiatric disorders was 36%, and annual frequency of occupational injuries was 10%. There was a wide variety of activities and occupational risks. The high prevalence of health problems identified in the study calls attention to the need for measures to promote and protect rural workers' health.